1. Field of the Invention
The present invention relates to a light emitting device, and more particularly, to a light emitting device with a micro-reflection structure carrier.
2. Description of the Prior Art
Light emitting devices are extensively applied to many fields. For instance, light emitting devices are utilized in optical displays, laser diodes, traffic lights, data storages, communication devices, illumination devices, and medical instruments. For developing light emitting devices, one of the most important issues is to raise light emitting efficiency of light emitting devices.
In US publication No. US 2002/0017652 A1, an AlGaInP light emitting device of an embedded micro-reflection structure is disclosed. Please refer to FIG. 1. FIG. 1 is a prior art AlGaInP light emitting device of an embedded micro-reflection structure. LM is a metallic layer, CS is a conductive substrate, LE is an epitaxial layer with a micro-reflection structure, and E1 is an electrode. An etching process is performed on the epitaxial layer to form the micro-reflection structure LE, wherein the shape of LE includes hemispheres or pyramids. The metallic reflection layer LM is deposited on the epitaxial layer LE. The top of LE is bonded with a conductive carrier, for instance, a silicon chip. An opaque substrate of the original LE is removed so that the light emitted to the opaque substrate can be emitted out. The micro-reflection structure can reflect the light emitted to the micro-reflection structure, hence increases the brightness of the light emitting device. Since the light emitting device is connected to a small part of the carrier at the top of the micro-reflector and the connecting area is small, the mechanical strength is not good enough which may cause the junction surface to be easily stripped off.
Furthermore, the micro-reflection structure is formed by performing etching process on the epitaxial layer, therefore the epitaxial layer has to grow to a predetermined thickness. If the epitaxial is not thick enough, it will have a detrimental effect on the reflection function of the micro-reflection structure. However, it takes a long time for the epitaxial layer to grow, hence the cost increases.